When Charles Darwin was writing The Origin of Species he knew there was a problem with what he was proposing. To be able to account for the many different species that had been found in Cambrian rock (rock less than 540 million years old), Darwin's theory of evolution by natural selection needed complex life to be far more ancient. He needed Precambrian life – he needed the Precambrian seas to be teeming with life.

He stated his concerns in The Origin of Species:

Consequently, if my theory be true, it is indisputable that before the lowest Silurian stratum was deposited, long periods elapsed, as long as, or probably far longer than, the whole interval from the Silurian age to the present day; and that during these vast, yet quite unknown periods of time, the world swarmed with living creatures. To the question why we do not find records of these vast primordial periods, I can give no satisfactory answer."

Unfortunately for Darwin, the accepted scientific view at the time, and right up to the 1950s, was that complex life emerged in the Cambrian period. It was thought the Cambrian explosion was the period in which most major animal phyla appeared and that Precambrian rock was largely devoid of life.

Then, in 1957, the evidence that Darwin sought was finally found. A group of schoolboys were rock climbing in a Charnwood Forest quarry and spotted what they thought was a fossil. They knew there weren't supposed to be any fossils in this type of rock – but they saw something that looked like a leaf. Fortunately, one of the boys was Roger Mason and he had a contact at Leicester University. Trevor Ford, a geologist at the university, confirmed the discovery and the following year a paper describing Charnia masoni was published in the journal of the Yorkshire Geological Society.

Since that discovery, Ediacaran fossils, as they are now called, have been found in only a handful of locations around the world. They are extremely rare, but Leicestershire can boast that it is home to several sites. The fossils are also extremely important – the discovery of Ediacaran fossils effectively proved Darwin was right. The Precambrian seas did indeed "swarm with living creatures" and there had been evolution for tens or hundreds of millions of years before the Cambrian explosion. In fact, there wasn't so much an "explosion" of life during the Cambrian, more a shift in preservation. The fossil evidence of the Precambrian is rare because the Ediacaran biota had soft bodies and no skeletons, which meant that they would only fossilise in perfect, chance, conditions. During the Cambrian, however, with the development of shells and skeletons, fossilisation was relatively more likely.

Dr Roger Mason standing in front of a Precambrian fossil bed in Bradgate Park, which has been damaged by graffiti. Photograph: Kash Farooq

The discovery made by Roger Mason – now Dr Roger Mason, a retired geologist – can be seen at Leicester's New Walk museum. Leicestershire's other Ediacaran fossils, however, are not so safe. One of the very accessible fossil beds is in Bradgate Park. "They are next to a path and over the years they have been marked by graffiti," says Dr Mason. But a more recent development, since about 2000, is that people have tried to take the fossils out using a hammer and chisel. You can't do this. The rocks have undergone metamorphism and deformation after they were deposited. If you try to collect them you just shatter the rock and destroy the fossils."

Previously, the only form of protection these delicate fossils had was to simply keep them secret; there was a policy of keeping the location of fossils confidential. This form of protection is clearly not good enough and is not working – new damage was discovered as recently as July of this year.

The Charnia Research Group has been in discussions with Natural England, which is responsible for Sites of Special Scientific Interest, about protecting the locations. Dr Mason is also trying to raise the profile of the fossils. In his article for the Geological Society he implores that "this truly world-class geological locality should be much more widely publicised. Visit it if you have not yet done so". He believes an informed public should play a major role in protecting the Charnwood fossils.

The fossils at Bradgate Park are astonishing. If you visit the fossil beds in the late afternoon, with the sun low in the sky but still bright, so that the light shines across the rock face, signs of life leap out at you – you can easily spot them. It is an incredible feeling looking at the fossils while keeping in mind that these are creatures that were alive more than 540m years ago.

Ediacaran fossil at Bradgate Park. Photograph: Kash Farooq

There are many options under consideration for how the fossil beds can be protected – hopefully Bradgate Park and Natural England will find a solution soon. There are not many places in the world where you can see the remains of Precambrian life, and Bradgate Park in Leicestershire has some of the finest examples. Fossil poaching and vandalism is being brought to our attention in places like China and Mongolia, but we must not overlook our own fossil heritage and the damage being done here. Dinosaurs may get the headlines, but we must look out for these beautiful and important specimens too.

• Kash Farooq is a software developer, a blogger at The Thought Stash and regular contributor to the weekly podcast Pod Delusion. He is studying astrophysics at Open University and you can find him on Twitter @kashfarooq. He interviewed Dr Roger Mason for episode 207 of the Pod Delusion.